Background: Daily stress and mood may influence eating behaviour, which may affect health outcomes in the long term.
Objective: To investigate the role of daily stress and mood on eating behaviour in a student population and to examine the moderating effect of trait characteristics on these associations.
Design: A daily diary survey was carried out over 21 days in 288 undergraduate students at the University of Otago. Students accessed a secure webpage each day and reported the type and intensity of their daily stress, mood, and daily eating behaviours. The moderating influence of Intuitive Eating, Mindfulness, Emotional Eating, Body Mass Index (BMI), gender, and dietary modification to lose or maintain weight were measured separately. Hierarchical linear modelling was used to examine associations between daily stressors, mood, and eating behaviour.
Results: On days when participants reported greater positive affect, they reported consuming more servings of fruit (p < 0.01) and vegetables (p < 0.001), yet they also perceived consuming more food than usual (p < 0.001). These associations were significant regardless of the intensity of positive affect experienced.
By contrast, experiences of daily stress and negative affect were associated with less healthy eating patterns. Greater total daily stress was associated with a lower number of servings of vegetables per day (p < 0.01), and also with less frequent consumption of cake, muffins, and buns (p < 0.05). On days when greater stress was experienced, participants also perceived themselves to consume less food than usual (p < 0.001). When types of stress were analysed separately, it was found that these associations were driven by experiences of work-related and physical stress (both p < 0.01). On the other hand, ego-threatening and interpersonal stress were associated with consuming more food, in particular ego-threatening stress was associated with consuming more fruits and vegetables (p < 0.05), and interpersonal stress was associated with consuming more chocolate-coated and cream-filled biscuits (p < 0.05).
On days when participants reported greater negative affect, they also reported consuming more servings of crisps, corn snacks, and corn chips (p < 0.05), and less fruit (p < 0.05), and this was driven by feelings of sadness and depression. BMI was positively associated with consuming more unhealthy foods on days when more stress and negative affect was experienced. No other moderators substantively altered the stress, mood, and eating associations.
Conclusion: The adverse association between ego-threatening and interpersonal stress or negative affect and unhealthy eating behaviour is consistent with previous research. A unique finding was the link between positive affect and higher fruit and vegetable consumption. Individuals with a high BMI may be at risk of unhealthy eating behaviours under stress and negative affect.
Source of Funding: University of Otago Research Grant.
